Opportunities and barriers for the estimation and prediction of soil carbon at State and catchment scales in New South Wales, Australia

Implementation of the the New South Wales Soil Condition Monitoring Program began in 2008/9. The program aims to assess a range of soil condition indicators but among these, soil carbon is considered to be the most important. Data from the program, gathered from more than 800 sites, across an area exceeding 800,000 km2, provide a unique opportunity to examine patterns and trends in soil carbon status across a wide range of climatic zones, soil types and land-uses. Here we explore this extensive, systematically collected soil carbon dataset. Examination of spatial variability has allowed the assessment of the precision and confidence of soil carbon estimates at site and regional scales and limitations in such estimates. Analysis of the depth distribution of soil carbon points to predictable profile partitioning of soil carbon across climate/soil-type/land-use combinations. Through analysis of this dataset, we present a potential rapid, efficient method for the estimation of soil carbon for carbon accounting at Catchment and State scales along with limitations and barriers to this approach.